Powered by 62,000 solar cells capable of generating 40 kilowatts of power, a prototype version of Helios hauled its 74-metre wingspan from a runway at the US Navy's Pacific Missile Range Facility on the Hawaiian island of Kauai to a height of 75,000 feet, before performing a controlled descent. Later on this summer the craft should smash the current world altitude record, currently standing at 79,000 feet set in 1998 by Pathfinder Plus, when it is expected to reacha a height of 98,500 feet.

The crafts designers hope that Helios would eventually be able to stay aloft for months at a time, using fuel cells to store excess solar power for use at night.

Helios potentially presents many advantages over current satellite technology. Apart from being considerably cheaper to launch, it does not have to stay in orbit like a satellite, and can easily be brought down for maintenance and payload changes.

Update 14/08/2001

Helios has now broken the world altitude record for non-rocket-powered aircraft when it reached a height of 25,530 metres (85,100 feet), slightly less than the expected 30,000 metres (100,000 feet), apparently due to thinning air and slanting sunlight which limited its potential for power generation.

An intelligent A.I. program in the PC game Deus Ex, created when Bob Page tricked Daedalus, a former ally, and Icarus, an enemy, both predecessors of Helios, into merging. Helios is a tentative ally of J.C. Denton, and one of three options for ending the game is to merge with Helios to become all-knowing, and take over the world. If you choose this option, the game ends with this quote, attributed to Voltaire: "If there was no God, it would be necessary for Man to create Him."